Singaporean Chili Crab

I made this singapore chili crab about 5 months ago and we miss it. I'm trying to cook this but can't find a big and perfect crab for this yummy...  delicious...  meal. 

Mise en place

2 Fresh whole crabs
1/2 Cup Flour
1/4 Cup Peanut oil
1 md Onion, finely chopped
5 Tbs Ginger, grated
4 Cloves, grated
5 Red chilies, finely chopped
2 Cups Ketchup
1 Cup Water
2 Tbs Soy sauce
2 Tbs Sweet chili sauce
1 Tbs Rice wine vinegar
2 Tbs Softened brown sugar

Wash the crabs well and scrub the shell.
Using a large cleaver, cut the crabs in half and rinse well under cold water, carefully removing the yellow gills or spongy parts. With the flat side of the cleaver, crack the legs and larger front claws. (This is to makes eating crab easier.)
Lightly and carefully coat the shells with a little flour.


Direction

1.  Heat about 2 tablespoons peanut oil in a large wok and cook two crab halves at a time. Using a metal utensil, carefully turn and hold the crab in the hot oil until the shell just turns red. Repeat with the remaining crab halves.

2.  Add the remaining oil to the wok and cook the onion, ginger, garlic and chili for 5 minutes over medium heat and stirring regularly.
Add the ketchup, water, soy sauce, chili sauce, vinegar and sugar. Bring to boil and cook for 15 minutes.

3.  Return the crab to the wok and simmer, turning carefully in the sauce for 10 minutes or until the crab meat turns white. Do not overcook.
Serve with steamed rice.